Multicontrol electric alarm



March 17, 1931. v. A. HERR 1,796,368

MULTICONTROL ELECTRIC ALARM Filed April so, 1926 33 33 INVENTOR BY V/NcE/VT/N HER/i 344/14] I ATTORNEYS Patented Mar. 17, 1931 UNITED STATES VINCENT A. HERE, COLLINSVILLE, ILLINOIS MULTIGONTROL ELECTRIC ALARM Application filed April 30,

My invention relates to improvements in thermal responsive electric circuit controls; more specifically to a thermostatic switch adapted for various uses, such as a fire alarm,

or for any purpose where it is desired to close or open an electric circuit at a predetermined temperature.

An object of my invention is to provide a simple and reliable thermostatic switch which will operate with certainty over a long period of years; one which is dependable, permanent and inexpensive to manufacture.

A further object is to provide a thermostat or fire alarm which may be adjusted to 16 operate at any predetermined temperature between wide limits, yet which will function with certainty at the temperature at which it is set to operate.

A further object of my invention is topro- 20 vide a device which is equally adaptable to either an open or a closed electric circuit.

Further objects and advantages of my in.- vention will appear from the drawing and the following description thereof.

In existing devices of this sort, it has been known to employ a member composed of two or more dissimilar metals having widely different coeflicients of expansion. In the presence of heat, the unequal expansion results in distortion of the composite member, and this distortion is used to make or break suitable electric contacts. Because of its relia bility, I employ an improved arrangement of this type, but to insure a quicker opening or closing of the circuit, I coordinate the above method with a novel spring impelled plunger device controlled by a fusible link, as hereinafter described. The combination of these two devices in the same apparatus, either of which is more than ordinarily dependable, results in a device which is positive in its operation. Any uncertainty of accurate adjustment, the possibility of a loose connection, the chances of incurring harmful effects from steam, dust or dirt, are all rendered of no practical consequence by the use of a doubly controlled apparatus in the same electric circuit. Any possible uncertainty in the action of the fusible link and plunger assembly, is precluded by the use of a plu- 1926. Serial No. 105,766.

rality of fusible links, in series, as hereinafter described.

In the drawing, Fig. 1 is a front elevation of an approved form of my device; Figs. 2 and 3, side and rear elevations respectively, and Fig. a is an elevation of one of the contact assemblies, as viewed along line ll of Fig. 1.

Referring by numerals to the drawings, 1 indicates a base for the assembly, which I pre for to construct of fibre, wood, vulcanite or of a condensation product. Any suitable material of requisite strength and dielectric properties may be used. Numerals 2, and 4 denote assembly bolts in the lever and plunger assembly 12. A series of bolts, indicated by 5, 6 and 7, serve to secure the plunger base and thermostat assembly to base 1. The thermostat is bi-met-allic and an associated contact 11 is preferably provided with an adjustment slot 9 and a locking bolt 8. The contact 11 is adjustably supported by a bolt 10, and 27 is a fixed contact attached by a bolt 36.

In the lever and plunger assembly 12, a plunger 13 is adapted to be forced downward b spring 14, retained by a washer or collar 1 The latter is positioned by a pin or cotter key 16. A lever 17, pivoted at 3, is dri led preferably as at 18 to receive a connection for a fusible link 29. The plunger 13 is preferably pointed on one end as at 19. This point will force its way through accumula tions of dust and make good contact with base 20, upon severance of link 29.

The bi-metallic thermostat member 22 is supported by a bolt 21, the latter being preferably slotted to receive the central portion of the member 22 which may be secured there in by a set-screw 38. I prefer to provide for angular adjustment of member 22 by a wing nut 23 or other like means. To member 22, I prefer to attach an arm or l ver 24 for making or breaking circuit by its motion toward or from the contact pieces 27 and 11. For open circuit work, arm 24 will move counterclockwise to make contact with 27. For closed circuit installation, the arm 24 may be adjusted to contact with 11, until the application of heat causes the circuit to be opened j by the separation of arm 24: from member 11. Obviously, I may rotate thermostat 22 by bolt 21, substantially half around so as to obtain the desired contacts for either open or closed circuit work between arm 24 and plunger base 20.

Referring again to the lever and plunger assembly, a suggested construction is shown by porting and positioning the plunger 13 in drilled supports or flanges 25 and 26.

The base 1 is preferably drilled at 28 to provide a hole for securing one end of the fuse link 29, the other end thereof being retained by insertion in a hole 18 in the long arm of lever described above. The length of the element :29 is so adjusted as to retain plungcr13 away from plate 20, with spring 14 substantially compressed. Element 29 includes as a part thereof any substance which will fuse the desired temperature. A va- "i f lble ink ri 1 l e i a l anl l. eU Y Oi niacin L181 A i S 1-0v3 Ow PluCc C furnished, which shall rovide a range of definite fusing temperatures.

1 may provide an additional fusible ele ment 30, for use in a. closed circuit system. This is preferably a fusible strip, connected between bolts 10 and S5, and serves to insure a break in the closed circuit system under the influence of heat. Fusible strip 30 is preferably mounted on the rear of the base and is spaced therefrom by fibre washers 39 or other suitable means.

A suitable wiring scheme is indicated by wires 31, 32 and 33. Some such securing means, as hold-fast 3%, may serve to retain the various leads against the back of the base. As'connecting and securing means, bolts 35, 36 and 37 are shown as conventional examples.

At 40 is shown an extension piece of insulating material, by which are carried a pair n L 1 O1. nxed mutually insulated contacts adapted to be bridged by a metallic contact strip carried by plunger 13, this strip being insulated from the plunger by a block of insulating material 41. his arrangement is used when the closed circuitsystem is employed.

ln adjusting the whole apparatus, the setting of the plunger assembly by proper choice of link 29, is such that the link will fuse and the plun er drop, at a slightly lower temperature than that at which the thermostat 22 will make or break the circuit.

The plunger action being much more rapid than th thermostat, such an adjustment will preclude any arcing between contacts. If desired, the plunger and thermostat may be adjusted to'operate simultaneously or in the inverse order.

It will appear that the apparatus as shown is wired completely for installation in either an open circuit system or a closed circuit system, connection being made to selected pairs of the wires 31, 82 and 33 according to the cir-- cuit arrangement desired, for example, the

leads 31 and 33 may be employed to connect the device into a closed circuit system, and the leads 31 and 32 employed for open circuit arrangements.

The operation of my device in an open circuit system is as follows: In the presence of sufficient heat, link 29 fuses and severe. Spring 1% impels plunger 13 so that its point 19 impinges upon element 20 to close the circuit. lmmediately thereafter, the circuit is further securely closed by contact between arm El and contact 27.

Where a closed circuit is employed, the downward movement of the plunger breaks the circuit between contacts carried by elements 40 and i1. The fusing of link 30 and the breaking of contact between arm 2% and either of contacts 2'? or 11, will result in a positive opening of tne closed circuit system.

Although my invention consists largely in the construction and arrangement of parts herein described anl particularly pointed out in the claims, yet I do not limit my invention to the precise form or construction of parts shown or the s veral parts thereof, inasmuch as various alterations may be made without changing the scope of my invention.

T claim 1. In a thermal responsive electrical device adapted selectively for open and closed circuits, a switch structure including a movable contact member, a plurality of fixed contact members, arranged for selective engagement by said movable member, and a tension element of fusible material whereby said movable member is lrept normally in engagement with one of said fixed contact members, and means, operative upon fusion of said tension element, for actuating the movable contact member away from said last named fixed contact and into engagement with anotherof the fixed contact members.

2. In a thermal responsive electric alarm, a switch structure adapted for connection into either an open. or closed circuit, said structure including fixed contact members; a movable contact member, arranged selectively to engage the fixed contacts, a spring arranged actuating the movablecontact toward one of its opposite positions, and a fusible link adapted to retain said movable contact member in inoperative position against the pressure of said spring,and in engagement with one of the fixed contacts.

3. 1n an electric heat-alarm, adapted for open andclosed circuituse, springbperated circuit controlling means comprising a switch, having a single movable circuit-controlling member, a plurality of fixed contacts, engageable selectively by said member, a tensioned fusible element normally keeping said member inoperative and means adapted to function upon fusing of said element to move said controlling member away from one of the fixed contacts and into engagement with another thereof.

4. In a thermal responsive electrical device, adapted selectively for open and closed cir- 5 cuit use, a switch structure including a pair of spaced stationary contacts and a spring pressed plunger adapted, upon actuation, to impinge upon one of said stationary contacts to close the switch when employed in a normally open circuit, and a fusible link whereby said plunger is normally retained out of engagement with said last named contact and kept in engagement with the other stationary contact, when the device is employed in a normally closed circuit.

5. In a thermal responsive electrical device, adapted selectively for open and closed circuits, a structure including in combination, means comprising a fusible element, a switch having a spring-pressed movable contact, a

plurality of fixed contacts limiting the actuation of the movable contact, and selectively engageable thereby, said movable contact being normally retained by said fusible element against one of the fixed contacts, and adapted to be biased into engagement with another fixed contact upon severance of the fusible element, and a pivoted lever connecting said fusible element and movable contact, and

having a shorter arm engaging the last named contact.

6. In a thermal responsive electrical device adapted for use selectively in an open, or in a closed circuit, the combination in a switch structure, of spaced, fixed contacts, a spring,

a lever, a fusible element and a springpressed, endwise movable contact engaging opposite ends of said lever, said movable contact adapted to be normally positioned by said lever and fusible element, in engagement with one fixed contact, another of said fixed contacts arranged to limit the movement of said contact by said spring, and electrically to coact therewith when the device is employed in a normally open circuit.

7. In a thermal responsive electrical device adapted for use in either a closed or open circuit, the combination of means comprising a lever, a switch structure including a pair of 5 fixed contacts, a movable contact member operatively'connected to the lever, and arranged to clear one of said fixed contacts as it moves to engage the other fixed contact, an element of fusible material connected to the 55 lever, whereby said movable member is normally held in inoperative position by said lever, and a spring, adapted to actuate the movable contact in a given direction to an operative position, irrespective of the circuit association of the device.

VINCENT A. HERB. 

